Air pollution has become a major problem, and many devices for cleaning or purifying exhaust gas have heretofore been suggested and/or utilized. While such devices have been suggested and/or utilized, for example, to remove particulate matter from the exhaust emitted by an internal combustion engine and from smoke stacks and the like of industrial plants, such devices have met only limited success, have been unduly complicated and expensive for general use, have not been adapted for readily cleaning and/or replacing filter sections while retaining intact other portions of the device, have proven inefficient and/or produced inconsistent results, have required reconstruction of the combustion system to accommodate the air cleaning device, and/or have imposed undue restrictions on the combustion system so as to make the combustion system virtually inoperable in its intended manner.
In known cleaning devices it has been common to employ a liquid to cleanse the exhaust gas. In one such arrangement, shown in U.S. Pat. No. 3,448,562, issued June 10, 1969 to Wisting, and U.S. Pat. No. 4,137,715, issued Feb. 6, 1979 to Tung-lung et al., screens of liquid through which a gas stream must flow are provided as a wetting agent for removal of particulates from the gas.
In a second such arrangement a reservoir of water is provided into which exhaust gas is vented for mixing with the water, the particulate matter in the gas settling out while the lighter gaseous matter rises for emission (see, for example, U.S. Pat. Nos. 4,282,017, issued Aug. 4, 1981 to Chen, 1,716,481, issued July 13, 1927 to Bilsky, 4,300,924 issued Nov. 17, 1981 to Coyle, and 4,002,136, issued Jan. 11, 1977 to Michalak). U.S. Pat. Nos. 3,815,328, issued June 11, 1974 to Moss, and 3,824,769, issued July 23, 1974 to Santos et al., show a combination filtering system involving use of both venting of exhaust gas into a water-filled reservoir as well as passage of the gas through a filter media. U.S. Pat. Nos. 3,548,591, issued Sept. 11, 1968 to Mckay, and 2,787,119, issued Apr. 12, 1955 to Giambruno, show the use of wetted filters for removal of matter from gas, while U.S. Pat. Nos. 3,417,549 and 2,932,157, issued Aug. 21, 1967 to Leosis and Apr. 12, 1955 to Villasenor et al., respectively, show the use of various other fluid-treated filters for the capture of particulates in exhaust gas.
In a third such arrangement, water is brought into contact with elements heated by hot exhaust gas for vaporization thereof (see, U.S. Pat. Nos. 2,737,260, issued Mar. 6, 1956 to Jenison, and 4,578,091, issued Mar. 25, 1986 to Borja, inventor herein and upon which the application is in part based). In neither case, however, is the hot exhaust gas used to heat the water directly for subsequent vaporization thereof.
Arrangements are also shown whereby heat is transferred from a hot gas to a fluid by contact of the gas with the fluid, but wherein the heating of fluids appears to be incidental (see, for example, U.S. Pat. Nos. 3,541,761 and 3,274,752, issued on Nov. 24, 1979 to Pike and Sept. 27, 1966 to Huyghe et al., respectively).
As may be appreciated from the foregoing, while devices for cleaning or purifying exhaust air have heretofore been suggested and/or utilized which make use of fluids for cleansing the exhaust air, further improvements could nevertheless still be utilized.